Centrifugal spinning process



April 11, 1939.

T. H. BYRON CENTRIFUGAL SPINNING PROCESS Original Filed July 30, 1934 Patented Apr. 11, 1939 2,153,823 GENTRIFUGAL SPINNING raoocss Thomas H. Byron, Elizabethton, Tenn, assignor to North American Rayon Corporation, New York, N. Y., a corporation of Delaware Original application July 30, 1934, Serial No. 737,499. Divided and this application June 11, 1936, Serial No. 84,661

4 Claims. (Cl. 18--54) This is a division of my application Serial Number 737,499, filed on July 30, 1934.

My present invention relates to the manufacture of yarn of cellulosic origin but more spe- Figure II is an enlarged cross-sectional view of my container for the drying of pot-spun yarn which has not already been dried.

Figure III is a detailed cross-sectional View of 5 cifically has for its object the continuous treatthe cover used with the container shown in Fig ment and drying of yarn produced in the spinure II. ning pot process. In the drawing in which like numerals of In the manufacture of artificial silk, a spinning reference indicate like parts, and referring spesolution of cellulosic origin is made up and excifically to Figure I of the drawing, I indicates m truded through the orifices of a spinning nozzle the yarn or filament bundle which is extruded into a coagulating or precipitating medium. The from the spinneret 2, located below the surface filaments thus formed are drawn therethrough of a precipitating bath 3. and passed to a spinning pot which simultanee fila e ts are drawn p y y t o ously twists and collects the yarn. er 5, over a guide roller 4. The drawing roller The resulting yarn body of the spinning pot 5 ro a es i a des p e pp b 15 process is built up from outside to inside and e in the trough l. A flowing bath arrangement when finished has the form of a dough-nut with (not shown) may b p y t t P a rectangular cross-section. This cake of yarn with the bath flowing over the entire surface of must be given different after-treatments such as e Teller 5 and being dra ed near the top of desulphurizing or decopping, deacidifying, etc. h trough 20 Due to its structure it has been the practice to From t e drawing roller 5 e ya is led to use inserts, such as resilient collars, for the pure second r l 8, r a in f r x p in a pose of reinforcing the unsupported yarn body Washing bath 9 contained in the trough Hi. This during the different treatment steps. Even then r l e 3 and t h y also e pp d e the yarn body was not sufficiently supported and flow bath arrangement d sc d th respect 25 a loss was suffered from collapsed cakes or tan- 0 e first should the yp of gled yarn layers. yarn being treated require more than two baths, In view of the foregoing, it is readily apparent these y be added Without altering the scope that the less handling the spinning cakes receive 0f t present ve t o the less resulting loss'there will be through dam- From the roller 3 the y is e Ov r the ro ler 30 a ed cakes, guide H and then downwardly to the collecting After the wet-treatment of the cakes, they not t. O e way downward the y passes must be dried. It is during the drying step through a heating tube l2, having perforations that inequalities in the yarn take place, due to shown at Here Warm air or other d y n uneven shrinkage. It has therefore been the medium is p d to t traveling yarn. The 35 practice to overcome this disadvantage by refilam ts fina y pas through the ary rewinding the yarn. By so doing an additional eipl'oeetihg guide indicated y to fo m the step is necessary which increases the production cake t, In operation the roller 8 may revolve at a faster 40 It is therefore one object of the present invene of speed than the take-11p T0116! e- 40 tion to lower the cost of production while km y stretching the yarn. A further advantage proving the quality of the yarn. lies in the fact that by rotating the roller 8 at Another object of the present invention is to a faster speed than the Speed of the p in produce pot-spun yarn or filaments in a conthe po Hi the yarn will be under no app 5 tinuous process. ciable tension when passing through the drying A further object of the present invention is to tube I2 and will therefore be able to shrink so produce pot-spun yarn that a twisted, treated freely. and evenly dried product is obtained with a min- The yarn thus wet treated and partially dried imum of steps. is collected in the pot l5. In Figures II and III These and other objects will in part become I have shown a means for drying the yarn thus 50 obvious and in part be pointed out in the folproduced so that no outside-inside shrinkage lowing specification and claims when taken in difiiculties occur. The pot I5 is perforated in I conjunction with the attached drawing, which: the bottom portion at I! and, after collection, Figure I is a diagrammatic side elevation of a top I8 is applied to the cake. This top I8 one form of the invention. comprises a non-foraminous ring provided with 55 a gasket I9, and the ring and gasket are so sized that they snugly fit the inner perpendicular surface face of the pct 15. A drying medium is passed upwardly through the perforations l1 and outwardly through the orifice 20 in the ring l8. Thus, the top, bottom and sides of the cake are sealed from the action of the drying medium, and the cake IE is dried from the inside only.

In Figure 111 I have shown a detailed view of the ring I 8, and a particular soft gasket L9 with a hollow space 2| is described. This gasket arrangement will be found to be sufflciently rigid to produce a fluid tight seal for the top of the cake l6, and will also be. adapted to sink with the cake should it shrink in size longitudinally during the drying step.

The ring l8 may be of Bakelite, hard rubber, non-corrodible metal, or other material not acted upon by the yarn.

Having now set forth my invention as required by the patent statutes, what I desire to claim is:

1. In a process for producing even shrinkage yarn, the steps of forming and treating the yarn, collecting it in a rotating pot, forming a fluid-tight seal for the under, outside and upper surfaces of the collected yarn cake, and then applying a drying medium to the inner side only of the cake so that it is dried from one side only.

2. In the production of even shrinkage yarn by the pot spinning method, the steps of extruding the yarn, passing it through a plurality of baths over rollers rotating at successively higher peripheral speeds, and then passing the yarn through a drying tube wherein the yarn is partially dried, and completing the drying in the collecting pot by so applying the drying medium that the yarn cake dries from one side only.

3. In a process of the type set forth, the steps of extruding yarn from a cellulosic solution, washing and simultaneously stretching the yarn, then partially drying the yarn under reduced tension prior to collection in a spin pot, collecting the yarn in a spin pot, and thereafter com-- pleting the drying by applying the drying medium to one side only of the cake produced in the pot while said cake is still in the pot.

4. In the continuous pot spinning process for the production of artificial yarn, the steps of extruding, wet-treating and stretching said yarn, then partially drying the yarn under reduced tension, and then completing the drying in the collected form by applying the second drying medium to one side only of the yarn body.

THOMAS H. BYRON. 

